Engine



INVENTOR.

ATTORNEY.

J. MEYER ENGINE Filed Dec. 26, 1951 Patented Apr. 28, 1936 ENGINE AndreJ. Meyer, Detroit, Mich., assignor to Continental Motors Corporation,Detroit, Mich., a corperation of Virginia Application December 26, 1931,Serial N 0. 583,288

3 Claims. (Cl. 123171) This invention relates to internal combustionengines and has particular reference to engines of the sleeve valve aircooled type, although many features of my invention are applicable toother types of engines.

My invention is especially suited for engines of the aircraft typewherein the air stream is conveniently employed to obtain enginecooling. In such arrangements it is customary to arrange the enginecylinders so that their axes are substantially transverse to thedirection of air stream flow so that the air stream sweeps across theouter ends of the cylinders. With such arrangements, the forward portionof the cylinder head, or that portion first receiving contact with theair stream is cooled much more effectively than rearward portions of thecylinder head since the air stream becomes heated by the forwardportions during travel of the air across the outer ends of thecylinders. This uneven cooling tends toward engine difficulties andinefiiciencies, particularly in connection with engines of the sleevevalve type which ordinarily employ cylinder head structures providedwith re-entrant portions extending inwardly of the respective cylinders.With such engines, this uneven cooling eifect tends to distort thecylinder heads resulting in a binding tendency in the sleeve valve meansand also resulting in improper cooling of the engine.

A further difliculty experienced in connection with engines of this typeresides in reverse-d cooling of the cylinder heads by reason of adisturbing influence produced by the screw bolts or other fastenersemployed to secure the cylinder heads on the respective cylinders. Thesefasteners customarily project outwardly from the cylinder heads in thepath of the air stream thereby preventing an efiicient flow of air incontact with the heated parts.

It is an object of my invention to provide improvements in engines ofthe aforesaid types so as to overcome the aforesaid difiiculties. Afurther object of my invention resides in the provision of a cylinderhead structure constructed and arranged to substantially compensate fortendencies of the air stream to cool the rearward portion lessefiiciently than the forward portion. A further object of my inventionin its more specific character resides in the provision of a cylinderhead structure having a plurality of spaced fins extending outwardlyinto the path of the air stream, the fins providing greater cooling areafor the rearward portion of the cylinder head structure than for theforward portion thereof.

A further object of my invention resides in the provision of a cylinderhead structure wherein the fastening devices are located away from thepath of the air stream across the cylinder ends whereby to materiallyincrease the cooling efiiciency of the engine by obtaining a relativelysmooth air stream flow.

A still further object of my invention resides in the provision ofimproved means for piloting a cylinder head structure in associationwith a cylinder structure so as to obtain improved alignment between thecylinder bore and re-entrant portion of the cylinder head structure.This feature of my invention relates to the provision of a cylinder headstructure having an undercut annular flange adapted for seating on theend of the cylinder and providing a cylindrical pilot engaging acompanion pilot formed with the cylinder structure, the pilot beinglocated relatively remote from the cylinder bore whereby it is veryeffective in properly aligning the cylinder and cylinder headstructures.

Other objects and advantages of my invention will be apparent as thisspecification progresses, reference being bad to the accompanyingdrawing in which:

Fig. 1 is a vertical elevation sectional view through a typical cylinderof the engine,

Fig. 2 is an elevation plan view of the cylinder head structure alone,and

Fig. 3 is a sectional elevation View along the line 3-3 of Fig. 2 andshowing one of the fastening devices for the cylinder head structure,and a portion of the associated cylinder structure.

In the drawing reference character A represents the cylinder structurehaving a cylinder bore it and a plurality of annular cooling fins iispaced axially of cylinder l around the outside of the cylinderstructure A. The structure A has an outer face i2 extending transverselywith the axis of cylinder ill and terminating outwardly in a cylindricalpilot l3. Located within the cylinder Ill is the sleeve valve means,herein illustrated as a single sleeve valve B formed with the usualintake and exhaust ports it and i5 respectively for cooperating in theusual manner with fuel mixture intake means It and exhaust gasconducting means ll respectively. The particular form of sleeve valvemeans is not important in this invention and I have therefore not illus-Operating within the sleeve valve B is the usual piston 58 andconnecting rod I9.

For closing the outer end of cylinder I0, I have provided a cylinderhead structure C which, in order to secure good heat conductingqualities, may be formed of a wall extending across cylinder Hi andhaving the annular flange 2| formed with radially outwardly extendingannular cooling fins 22 spaced axially of cylinder H2. The flange 2i isalso undercut to provide an annular seating portion 23 adapted to seaton outer face l2 of the cylinder structure A. The undercut seatingportion 23 also forms the annular or cylindrical pilot 24 adapted toengage the pilot l3 as shown in Fig. 1. The cylinder head structure ispreferably of the solid wall type and is formed with the generallycylindrical shaped depending portion 25 extending inwardly within andspaced from cylinder I 0 so as to form a sleeve pocket receiving theupper end of the sleeve valve as shown.

The wall 26 has an outer floor 26 from which are extended outwardlytherebeyond a plurality of cooling fins 21 preferably substantiallyaligned in the direction of the air stream indicated by arrows 23, thefins extending transverse to the cylinder axis. As shown in Fig. 1 thefins 21 are of less height at the forward portion 29 of the cylinderhead structure than at the rearward portion 38 so as to provide agreater fin area rearwardly than forwardly and thereby compensate fortendencies of said air stream to cool the rearward portion lessefficiently than the forward portion. In Fig. 1, I have illustrated thefins El as tapering progressively inwardly toward the oncoming airstream, thereby obtaining a progressive or gradual differential in the.cooling effect to substantially offset the differential cooling effectaforesaid. It will be understood that I have illustrated only onecylinder of the engine and it is frequently customary to form thecylinders radially about the axis of a common crankshaft (not shown),with the air stream flowing toward the exhaust side of the cylinders asillustrated in Fig. 1.

The flange M is formed with a circumferential series of spaced holes 3!formed with outer counterbores 32 adapted to receive the screw bolts orfasteners 33 with the heads 34 thereof respectively substantially housedwithin the counterbores 32. With such construction it will be noted thatthese fasteners do not present any disturbing eifect to the air streamas the air flows smoothly and efiiciently across the cylinder headstructure between fins 2?. The inward threaded portions of fasteners 33engage correspondingly threaded recesses formed in the outer end of thecylinder block structure as shown in Fig. 2. The wall 26 is formed withone or more recesses 35 for receiving the spark plugs 36. The sparkplugs have their terminals adapted to project into the combustionchamber 31.

It will be noted that the companion piloting portions l3 and 24 arelocated relatively remotely from cylinder bore Ill whereby a relativelysmall amount of piloting is very eifective in aligning the dependingportion 25 accurately with respect to cylinder Hi, assisted by theundercut face 23 engaging outer face E2 of the cylinder structure. As aresult of my improved piloting construction, the cylinder head isaccurately aligned and .does not tend to become distorted on beingseated by the fasteners 33 and thus there is no binding action on thesleeve valve means which would otherwise tend to be produced.

By reason of my annular flange 2| formed with the spaced annular fins22, I have provided a very efficient cooling for the cylinder headstructure, the fins 22 forming substantially a continuation of the finsH formed on the cylinder structure.

Furthermore by graduating the area of fins 21 with respect to theirproximity to the air stream 28, I have provided a cylinder headstructure which is substantially uniformly cooled, thereby obviatingtendencies toward distortion and binding of the sleeve valve means whichwould otherwise result under localized heating. The depending portion 25is preferably of the solid wall type in the interests of eflicient heatconductivity, as distinguished from the jacketed type of re-entrantportion.

Instead of having faces 23 and E2 in direct seating engagement, thesefaces may have a gasket interposed therebetween but this is not deemednecessary especially for the air cooled type of engine as illustrated.

Various changes and modifications will be apparent from my disclosureand it is not my intention to limit my invention to the specificarrangements of parts as shown and described.

What I claim as my invention is:

1. In an internal combustion engine of the air cooled type having acylinder structure provided with a cylinder, a cylinder head structureclosing one end of said cylinder and having an annular flange seated onthe outer end of the cylinder structure, said flange carrying aplurality of outwardly extending cooling fins and having a plurality ofcounterbored holes extending therethrough, and headed fastenersextending through said holes for connection to said cylinder structure,the heads of said fasteners lying substantially within said counterboresrespectively to provide smooth air flow across said cylinder structurein the vicinity of said fins.

2. In an internal combustion engine of the air cooled type having acylinder structure provided with a cylinder, a cylinder head structureclosing one end of said cylinder and having a wall extending across theouter end of the cylinder structure, said wall having a plurality ofcounterbored holes therethrough and a plurality of cooling fins adjacentthereto, headed members in said holes connecting the cylinder headstructure and cylinder structure, said members having their headspositioned in said counterbores to facilitate flow of cooling airintermediate said fins.

3. In an internal combustion engine of the air cooled type having acylinder structure provided with a cylinder, a cylinder head structureclosing one end of said cylinder and having a wall extending across theouter end of the cylinder structure, said wall having a plurality ofcounterbored holes therethrough and a plurality of cooling fins adjacentthereto, headed members in said holes connecting the cylinder headstructure and cylinder structure, said members having their headspositioned in said counterbores to facilitate flow of cooling airintermediate said fins, said wall also having a plurality ofcircumferentially outwardly extending cooling fins.

ANDRE J. MEYER.

